This is an expansion of an idea I saw here http://weblogs.asp.net/guybarrette/archive/2008/05/25/using-gmail-as-a-backup-mail-server.aspx
I have a small business with one server running SBS 2008 and I want email redundancy so that I don’t miss any email while my server is down for maintenance, power failure, etc. I also don’t want the hassle of periodically checking my off-site email address to see if anything has end up there, hence, I want a mail queue.
- Sign up for Google Apps email account (www.google.com/a).
- Replicate your user accounts on the Google mail. You may as well use the one administrator password for all accounts because users will never need to log in themselves.
- Assign your secondary MX records to point to the Google addresses specified in the settings they give.
At this point, Google will receive your mail if your server is unreachable.
- On the SBS Console, click the Netwtorking tab, then the Connectivity tab
- Setup the SBS POP 3 Connector using the information available in the Google settings for each account
- Setup the POP/Forwarding in each Google account and you’re done!
So now, if your server is unreachable, Google will get your mail. When your server is back up, it will query the Google inboxes at the intervals you specified and forward your mail to where it needs to go!